Hanno I agree entirely with you that the pig "is an obvious descendent of C15TA". This should be acknowledged more widely, it is particularly obvious when you look at the real Mk 1 which is the FV1609 with its canvas roof at the rear.
I have never seen a white Pig in British Army service in Cyprus, all the ones I have seen were sand colour.
The Bridge Classification is intriguing. I spoke to a veteran who explained. Makarios et al sort to place restrictions on the use of heavy vehicles on the basis that many bridges were unable to withstand the weight of such heavy vehicles. Overnight the Bridge Classifications were reduced & bridges were thus able to withstand the weight of Pigs falling from '6' to '5' & then even '4'.
One always has to evaluate stories told by veterans. I am sometimes told all sorts of nonsense by apparent veterans who have an answer for everything & sometimes seem to improvise. But the vet told the above story was most believable, not only because he told me other details that I knew to be correct but for a couple of my questions he had the honesty to say "I'm sorry I don't know".
When someone has the courage to say that, then to my mind their credibility goes shooting up. I am always circumspect of someone who has an answer for everything who will often fail on 'test' questions I pose, which is a terrible shame because there may be some useful info but I can't trust it.